Time Difference: Paris and London
London is 1 hour behind Paris, all year. When it's 9:00 AM in Paris, it's 8:00 AM in London.
Clock changes: France and the UK change their clocks on the same weekends, the last Sunday in March and the last Sunday in October, so London is always 1 hour behind Paris.
Take One Hour Off
If you start in Paris, take one hour off to get London time. Paris uses CET in winter and CEST in summer, and London uses GMT and BST, so the offset is a steady one hour: 5:30 PM in Paris is 4:30 PM in London. That is why this pair doesn't need a winter column and a summer column.
The easy mistake is adding the hour instead of subtracting it. A Paris 2:00 PM call is 1:00 PM in London. Going the other way, 9:00 AM in London is 10:00 AM in Paris, so Paris is already an hour into its day when London starts.
The date can still slip near midnight. 12:15 AM in Paris is 11:15 PM the previous day in London, so a message stamped just after midnight in Paris can show as the day before to a London reader.
Paris to London Hour by Hour
Each column is one real season of the Paris-London gap. Pick the column that matches your date.
| 🇫🇷 Paris (CET) | 🇬🇧 London (CET/CEST → GMT/BST) |
|---|---|
| 00:00 | 23:00(prev day) |
| 03:00 | 02:00 |
| 06:00 | 05:00 |
| 09:00 | 08:00 |
| 12:00 | 11:00 |
| 15:00 | 14:00 |
| 18:00 | 17:00 |
| 21:00 | 20:00 |
- CET/CEST → GMT/BST: every day of the year, because France and the UK change clocks on the same weekends
* "next day" / "prev day" = the converted time falls on a different calendar date.
Nine Until Five on Both Sides
With 9-to-5 days on both sides, the shared window begins at 10:00 AM in Paris, when London opens, and runs to 5:00 PM in Paris. That's 9:00 AM to 4:00 PM in London. Paris finishes an hour before London does, so after 5:00 PM Paris time it's only 4:00 PM in London and the London team may still be working.
Scheduling a London Review From Paris
A Paris team that needs a London review after lunch has an easy job. A 2:00 PM start in Paris is 1:00 PM in London, and a 4:00 PM start is 3:00 PM. The Paris team finishes first, so the later you go, the more London is the side that's still at work.
If London hosts at 9:00 AM, Paris joins at 10:00 AM. That's an hour into the Paris day, so that call is easy for Paris. A London call at 5:00 PM is 6:00 PM in Paris, after the Paris team's usual close.
For a weekly meeting, 11:00 AM Paris time is a reliable slot. It's 10:00 AM in London, and the shared window from 10:00 AM to 5:00 PM Paris is 9:00 AM to 4:00 PM in London.
For a recurring Paris-led call, write the invite with both times: "Weekly, 11:00 AM Paris / 10:00 AM London". The gap never moves, so the pair stays correct. If someone proposes a time without naming a city, ask which clock they used before you accept the invite.